Traditional cameras only capture imagery from a single, fixed perspective—the location of the camera lens's entrance window, which is the image of the aperture through the front of the lens. Light enters the camera lens, passes through the aperture, and forms an image, generally on a light-sensitive medium that records the image. Each pixel or region in the resulting recorded image represents all the light collected at that point on the sensor or film, and creates an image from the perspective of the lens's aperture.
In order to serve multiple views (as required for virtual reality, augmented reality, or holographic displays), the source imagery must contain multiple perspectives. One approach to capturing multiple perspectives may be to utilize an array of cameras, for example, each capturing a single perspective. Interpolating the view between cameras, however, may produce errors and may fail to capture specularity and proper parallax. Importantly, any approach that utilizes multiple camera lenses will under-sample and alias the light field, because the cameras are not continuous and the lens's apertures block out some of the light. There is an unfortunate tradeoff between fidelity of the light field reconstruction and the number of cameras required to capture the light field, and holographic imaging with arrays of cameras is impractical with today's camera technology. Additionally, other drawbacks to array-based capture solutions include high data rates, the requirement to synchronize camera elements, and the like.
Thus, there is a need for a device and method for capturing a holographic light field. The device may be an imaging device that seeks to sample the entire light field—all or most of the light that strikes an extended surface—in order to recreate any possible view that may be seen through that surface. A light field generally represents a large amount of potential data, although the light field may be substantially redundant. Preferably, this imaging device may optically alter a light field in order to capture it with significantly less data and reconstruct it with little to no error while sampling the entire light field.